In addition to well-known Covid-19 mutations like those from South Africa, Berlin, Romania and others around the world, a new variant has been detected in northern Bulgaria and the Bulgarian health authorities are now studying it.

In an interview with Nova TV, immunologist Acad. Bogdan Petrunov commented that due to the great variability of the virus, a fourth wave of Covid-19 was possible and it could require constant development of new vaccines. The immunologist is rather skeptical when it comes to herd immunity at the backdrop of the current pace of immunization.

Acad. Petrunov adds that some of the pharmaceutical companies have already started developing a third dose of the vaccine, which is to be administered in November.